This study presents the development of a novel sodium cathode filament for Fused Filament Fabrication (FFF). The filament formulation utilized polylactic acid (PLA) as the polymer matrix and sodium vanadium phosphate (NVP) as the active material, with poly(ethylene glycol) dimethyl ether (PEGDME) and carbon black Super P added to enhance plasticity and conductivity. The optimal composition was determined using a mixture design approach within the Design of Experiments (DoE) framework. An environmentally friendly methodology was adopted by avoiding conventional solvents during filament preparation. High-power ball milling was employed for efficient mixing and particle size reduction. An initial cathode mixture was prepared based on the DoE matrix and evaluated for capacity. Homogeneity and elemental distribution were analyzed using scanning electron microscopy (SEM) and Raman spectroscopy